Robust temperature sensing in complex thermal scenarios using an all-fiber probe with erbium/ytterbium co-doped tellurite glass

Accurate thermal monitoring in complex environments is often hindered by various interferences. This study presents a miniaturized, robust fiber-optic temperature sensor based on green up-conversion fluorescence from erbium/ytterbium co-doped tellurite glass. Fabricated through a feasible fiber drawing and adhesive bonding approach, the sensor operates on the fluorescence intensity ratio FIR technique, exhibiting a reproducible response from −19.2 to 80.4 °C with a sensitivity of 8.34 × 10 −3  K −1  at 310 K and a 4 s response time. The sensor's reliability has been verified through real-time monitoring of human skin temperature and electronic chip thermal management. Furthermore, its ability to track photothermal effects highlights its potential as a miniature temperature feedback component in high-power UV systems. This work establishes a versatile and practical sensing solution for demanding thermal monitoring applications.